Cyclic shear resistance for seismic design, based on monotonic shear models in fib Model Code 2010 and in the 2018 draft of Eurocode 2

2019 ◽  
Vol 21 (1) ◽  
pp. 129-150 ◽  
Author(s):  
Dionysis Biskinis ◽  
Michael N. Fardis
Keyword(s):  
Seismic Design ◽  
Shear Resistance ◽  
Cyclic Shear ◽  
Model Code ◽  
Eurocode 2 ◽  
Model Code 2010

scholarly journals Theoretical prediction of punching shear capacity of flat slabs without shear reinforcement strengthened by concrete topping

2021 ◽  
Vol 1203 (2) ◽  
pp. 022108
Author(s):  
Daniel Čereš ◽  
Katarína Gajdošová
Keyword(s):  
Shear Resistance ◽  
Design Guidelines ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Model Code ◽  
Flat Slabs ◽  
Eurocode 2 ◽  
Model Code 2010

Abstract The main reasons for strengthening flat slabs are the change of the use of a building, increase in the value of loads, degradation of the concrete cover layer, or insufficient reinforcement. This paper is focused on the assessment of punching shear capacity of the strengthened flat slabs without shear reinforcement. One of the possibilities how to enhance punching shear capacity is the addition of reinforced concrete topping. The main goal of this paper is to compare the possibilities for calculation of the increase in the punching shear capacity by investigation of the influence of different thicknesses of concrete toppings and different reinforcement ratio. A reference specimen is represented by a fragment of a flat slab with the thickness of h = 200 mm supported by circular column with the diameter of 250 mm. Three different thicknesses (50 mm, 100 mm, 150 mm) of concrete toppings were considered together with three different reinforcement ratios for each thickness of concrete overlay. Theoretical predictions of the punching shear resistance of flat slabs were evaluated by design guidelines according to the relevant standards: Eurocode 2 (EN 1992-1-1), Model Code 2010 and draft of the second generation of Eurocode 2 (prEN 1992-1-1). The differences in the influence of reinforcement ratio are significant. In Model Code 2010 the reinforcement ratio in concrete topping was considered in equation of moment of resistance. This is unlike in both of the mentioned Eurocodes, where the reinforcement ratio was assumed as a geometric average value of the original reinforcement ratio in the slab before strengthening and of the reinforcement ratio of concrete topping. All the predicted theoretical calculations are based on the perfect connection and bond between the original and new layer of concrete. These predictions should be verified by experimental investigation, which is going to be prepared shortly. By the additional increase in the thickness of concrete topping or in the amount of added reinforcement the attention should be payed to the limitation of the punching shear resistance by the value of the maximum punching shear resistance in the compression concrete strut.

scholarly journals Strengthening flat slabs without shear reinforcement against punching shear by concrete overlay

2021 ◽  
Vol 1209 (1) ◽  
pp. 012056
Author(s):  
D Čereš ◽  
K Gajdošová
Keyword(s):  
Parametric Study ◽  
Shear Crack ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Punching Shear ◽  
Flat Slab ◽  
Model Code ◽  
Eurocode 2 ◽  
Model Code 2010

Abstract Research in this paper presents a theoretical study of increasing in punching shear capacity of the strengthened flat slab by concrete overlay. The parametric study is based on comparison of three different relevant standards design models and presents results how Eurocode 2 (EN 1992-1-1), Model Code 2010 and draft of second generation of Eurocode 2 (prEN 1992-1-1) take into account strengthening by concrete overlay. A reference specimen is represented by a fragment of a flat slab supported by circular column. Influence of concrete toppings depends on thickness and also on reinforcement ratio. In Eurocode 2 and new generation of Eurocode 2 the increase of punching shear resistance of the slab with concrete topping can be taken into account only by reinforcement ratio and thickness of the slab considering the perfect connection and bond between the original slab and new layer of concrete overlay. Model Code 2010 is based on Critical shear crack theory and the reinforcement ratio in concrete topping was considered in equation of moment of resistance and punching shear resistance is calculated by considering the rotation and deformation of the slab. Estimation of results by parametric study are compared by non-linear model from Atena software.

scholarly journals Analysis of the Shear Resistance in the Indented Interface Between Two Concrete Parts of Concrete Composite Beam

2021 ◽  
Vol 31 (1) ◽  
pp. 93-105
Author(s):  
Grzegorz Sadowski ◽  
Piotr Wiliński ◽  
Anna Halicka
Keyword(s):  
Composite Beam ◽  
Correlation Method ◽  
Shear Resistance ◽  
Image Correlation ◽  
Actual Behavior ◽  
Construction Joint ◽  
Model Code ◽  
Eurocode 2 ◽  
Model Code 2010 ◽  
Calculation Results

Abstract This paper presents a comparative analysis of shear resistance in the interface between two concrete parts of concrete composite beam. The construction joint was performed as indented one in accordance with Eurocode 2 and fib Model Code 2010. The numerical calculation results were confronted with the actual results of tests of a composite beam subjected to 4-point bending. The displacement values of tested element were obtained using dial sensors and the digital image correlation method (DIC). The analysis shows that the recommendations of Eurocode 2-1-1 and fib Model Code 2010 do not reflect the actual behavior of concrete composite beam with indented surface.

scholarly journals Punching strength of reinforced concrete flat slabs without shear reinforcement

2012 ◽  
Vol 5 (5) ◽  
pp. 659-691 ◽  
Author(s):  
P. V. P. Sacramento ◽  
M. P. Ferreira ◽  
D. R. C. Oliveira ◽  
G. S. S. A. Melo
Keyword(s):  
Reinforced Concrete ◽  
Shear Crack ◽  
Theoretical Method ◽  
Shear Reinforcement ◽  
Model Code ◽  
Flat Slabs ◽  
Codes Of Practice ◽  
Eurocode 2 ◽  
Model Code 2010 ◽  
Theoretical Results

Punching strength is a critical point in the design of flat slabs and due to the lack of a theoretical method capable of explaining this phenomenon, empirical formulations presented by codes of practice are still the most used method to check the bearing capacity of slab-column connections. This paper discusses relevant aspects of the development of flat slabs, the factors that influence the punching resistance of slabs without shear reinforcement and makes comparisons between the experimental results organized in a database with 74 slabs carefully selected with theoretical results using the recommendations of ACI 318, EUROCODE 2 and NBR 6118 and also through the Critical Shear Crack Theory, presented by Muttoni (2008) and incorporated the new fib Model Code (2010).

scholarly journals Estudo comparativo entre valores teóricos e resultados experimentais de módulo de elasticidade de concretos produzidos com diferentes tipos de agregado graúdo

2017 ◽  
Vol 17 (3) ◽  
pp. 281-294 ◽  
Author(s):  
Antonio Carlos dos Santos ◽  
Angela Maria de Arruda ◽  
Turibio José da Silva ◽  
Paula de Carvalho Palma Vitor
Keyword(s):  
Model Code ◽  
Eurocode 2 ◽  
Model Code 2010

Resumo O módulo de elasticidade do concreto é uma propriedade importante para os profissionais envolvidos na indústria da construção civil, uma vez que seu valor é determinante para o controle das deformações. Este trabalho avaliou o módulo de elasticidade de três classes distintas de concreto (C20, C30 e C40) produzidas com dois tipos litológicos de rochas, basalto e dolomito, de diferentes jazidas da região do Triângulo Mineiro. Como parte do estudo experimental, foram moldadas 324 amostras cilíndricas de 10 cm × 20 cm. Os valores de módulo de elasticidade obtidos foram comparados com seis formulações propostas em quatro normas, institutos e códigos do concreto: ABNT NBR 6118 versão 2007 e 2014, ACI 318, EUROCODE 2 and FIB Model Code, Ibracon 2003. Dentre as formulações propostas pelas normas, as indicadas pela FIB Model Code (2010) e ABNT NBR 6118 (2014) apresentaram valores mais próximos aos resultados experimentais deste estudo.

scholarly journals Behaviour of recycled aggregate concrete under combined compression and shear stresses

2018 ◽  
Vol 68 (331) ◽  
pp. 162
Author(s):  
K. Liu ◽  
J. Yan ◽  
C. Zou
Keyword(s):  
Failure Criterion ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Shear Stresses ◽  
Aggregate Concrete ◽  
Model Code ◽  
Eurocode 2 ◽  
Model Code 2010 ◽  
Normal Strength

To investigate the behaviour of recycled aggregate concrete (RAC) under combined compression and shear stresses, 75 hollow cylinder specimens prepared with various replacement ratios of recycled coarse aggregate (RCA) were tested with a self-designed loading device. The results showed that the failure pattern was similar for RAC with different replacement ratios of RCA. The ultimate shear stress improved with an increasing axial compression ratio of less than 0.6 and declined after exceeding 0.6. A modified failure criterion for RAC with normal strength under combined compression and shear stresses was proposed. A new procedure to predict the shear strength for RAC beams without stirrups was developed based on the proposed failure criterion, showing a better correlation with the experimental results than the predictions calculated by GB50010, Eurocode 2, fib Model Code 2010 and ACI 318-11.

scholarly journals The influence of longitudinal reinforcement on shear capacity of reinforced concrete members without shear reinforcement

2014 ◽  
Vol 13 (3) ◽  
pp. 151-158
Author(s):  
Marta Słowik
Keyword(s):  
Reinforced Concrete ◽  
Shear Capacity ◽  
Longitudinal Reinforcement ◽  
Test Results ◽  
Shear Reinforcement ◽  
Professional Literature ◽  
Model Code ◽  
Concrete Members ◽  
Eurocode 2 ◽  
Model Code 2010

In the paper, the influence of longitudinal reinforcement on shear capacity of reinforced concrete members without shear reinforcement is discussed. The problem is analyzed on the basis of the author’s own test results and tests results reported in the professional literature. It has been concluded that longitudinal reinforcement has an effect on shear capacity especially in members of shear span-to-depth ratio a/d < 2,5. The test results have also been used to verify standard methods of calculating the shear capacity in reinforced concrete members without shear reinforcement given in Eurocode 2, ACI Standard 318 and Model Code 2010.

scholarly journals Reliability-based assessment of the partial factor for shear design of fibre reinforced concrete members without shear reinforcement

2021 ◽  
Vol 54 (5) ◽  
Author(s):  
Jesús Miguel Bairán ◽  
Nikola Tošić ◽  
Albert de la Fuente
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Resistance ◽  
Fibre Reinforced Concrete ◽  
Shear Reinforcement ◽  
Model Code ◽  
Shear Design ◽  
Model Code 2010 ◽  
Partial Factor ◽  
Failure Probabilities

AbstractFibre reinforced concrete (FRC) is increasingly used for structural purposes owing to its many benefits, especially in terms of improved overall sustainability of FRC structures relative to traditional reinforced concrete (RC). Such increased structural use of FRC requires safe and reliable models for its design in ultimate limit states (ULS). Particularly important are models for shear strength of FRC members without shear resistance due to the potential of brittle failure. The fib Model Code 2010 contains a model for the shear strength of FRC members without shear reinforcement and the same partial factor accepted for RC structures is accepted for FRC elements. This approach, however, is potentially on the unsafe side since the uncertainties of some design-determining mechanical properties of FRC (i.e., residual flexural strength) are larger than those for RC. Therefore, in this study, a comprehensive reliability-based calibration of the partial factor γc for the shear design of FRC members without shear reinforcement according to the fib Model Code 2010 model is performed. As a first step, the model error δ is assessed on 332 experimental results. Then, a parametric analysis of 700 cases is performed and a relationship between the target failure probability βR and γc is established. The results demonstrate that the current model together with the prescribed value of γc = 1.50 does not comply with the failure probabilities accepted for the different consequences of failure of FRC members over a 50-year service life. Therefore, changes to the shear resistance model are proposed in order to achieve the target failure probabilities.

Sign in / Sign up

Export Citation Format

Share Document